The cooling turn performed last week by the Galileo spacecraft did not result in low enough temperatures to release the few antenna ribs apparently bound by friction to the antenna's central tower, Galileo project officials said today.

Another cooling turn is being planned for December 1991 when Galileo is farther from the sun; additional actions will be taken at that time to cool the antenna tower further. These cooling turns are part of a series of steps the project believes will be required ultimately to deploy the antenna, the officials said; each step yields valuable data to help with the design of spacecraft actions in the next step.

For the next two months, the Galileo flight team will concentrate on the final preparations for Galileo's October 29 encounter with the asteroid Gaspra. This will be the first spacecraft asteroid encounter.

Galileo's high-gain antenna is not essential for mission operations until the spacecraft is in orbit around Jupiter in December 1995, project officials said.

The Galileo project is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.